Estrogen Induced Gene 121 (EIG121)

EIG121 was upregulated 2- to 3-fold in postmenopausal endometrium in response to estrogen replacement. The predicted 1,013-amino acid EIG121 protein is 90% identical with the mouse ortholog, and related sequences are seen in fish, Xenopus, chicken, and C. elegans.

The level of EIG121 was an average of 3.8-fold higher in endometrial hyperplasias and 21-fold higher in grade 1 tumors. Expression was 3.5-fold higher in grade 3 endometrioid carcinoma than in benign endometrium and tended to decline with increasing tumor grade and disease stage. Immunohistochemical staining with an antibody to EIG121 showed faint staining of normal endometrial epithelium and intense staining of endometrioid tumors.